US6910261B1 - Method of fabricating a colossal magneto-resistive detector using a thin film transfer method - Google Patents

Method of fabricating a colossal magneto-resistive detector using a thin film transfer method Download PDF

Info

Publication number
US6910261B1
US6910261B1 US10/805,669 US80566904A US6910261B1 US 6910261 B1 US6910261 B1 US 6910261B1 US 80566904 A US80566904 A US 80566904A US 6910261 B1 US6910261 B1 US 6910261B1
Authority
US
United States
Prior art keywords
rock salt
salt structure
layer
substrate
structure material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US10/805,669
Inventor
Meimei Z. Tidrow
Steven Tidrow
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Department of Army
Original Assignee
US Department of Army
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Department of Army filed Critical US Department of Army
Priority to US10/805,669 priority Critical patent/US6910261B1/en
Assigned to SECRETARY OF THE ARMY, UNITED STATES OF AMERICA AS REPRESENTED BY THE reassignment SECRETARY OF THE ARMY, UNITED STATES OF AMERICA AS REPRESENTED BY THE ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TIDROW, MELMEI, TIDROW, STEVEN
Application granted granted Critical
Publication of US6910261B1 publication Critical patent/US6910261B1/en
Adjusted expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
    • G01J5/20—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
    • H01C17/06—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base
    • H01C17/075—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base by thin film techniques
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49082—Resistor making
    • Y10T29/49101—Applying terminal
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49117—Conductor or circuit manufacturing
    • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/49126—Assembling bases
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49117—Conductor or circuit manufacturing
    • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49117—Conductor or circuit manufacturing
    • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
    • Y10T29/49147—Assembling terminal to base
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49799—Providing transitory integral holding or handling portion

Definitions

  • This invention relates generally to uncooled infrared detectors and focal plane arrays, and more specifically to a method of fabricating a detector using rock salt as a removable substrate.
  • the invention relates even more specifically to a method of fabricating a colossal magneto-resistive detector using a rock salt structure material.
  • a microbolometer-type FPA typically employs vanadium oxide on silicon nitride with a micro-mechanically machined air bridge structure. The temperature coefficient of resistance for vanadium oxide is approximately 2%.
  • the air bridge structure is built directly on a silicon readout integrated circuit (“ROIC”). Growth of detector materials directly on the ROIC restricts the material thin film growth temperature to less than 550° C. as a result of the thermal budget limitation associated with the ROIC.
  • CMR colossal magneto-resistive
  • CMR materials have a perovskite crystal structure with a square base.
  • the lattice constant “a” of the square base of a CMR material is approximately 3.8 to 3.9 ⁇ depending on the material composition.
  • CMR thin films have been successfully grown on perovskite oxide substrates such as LaAlO 3 and SrTiO 3 , and exhibit a good crystal orientation and a high temperature coefficient of resistance. These perovskite oxide substrate materials are employed because of the correspondence of their crystal structure and lattice constant to those of CMR materials.
  • SrTiO 3 has a cubic crystal structure with a lattice constant of 3.905 ⁇
  • LaAlO 3 has a pseudo-cubic crystal structure with a lattice constant of 3.79 ⁇ .
  • the present invention advantageously relates to a method of fabricating a CMR detector using a thin film transfer method with a rock salt structure material as a substrate.
  • the method comprises (a) growing a protective layer comprising a lattice matched template material so as to envelop a rock salt structure material substrate; (b) depositing a colossal magneto-resistive layer on a deposition surface of the protective layer; (c) fabricating a detector array (d) bond the detector array to a ROIC; and (e) removing the rock salt structure material substrate from the bonded structure.
  • a rock salt structure material such as, for example, NaCl, LiF, NaF, KF, or KCl
  • a high quality epitaxial CMR material with a high temperature coefficient of resistance can be fabricated.
  • the substrate can be easily removed using water, and the excess rock salt structure material/water solution can then be removed by a method such as evaporation, triple-point, or freeze drying.
  • the present invention relates to a method in which a perovskite oxide material such as, for example, LaAlO 3 or SrTiO 3 is employed as the substrate, and the rock salt structure material is employed as a buffer layer, template layer, and release layer.
  • a perovskite oxide material such as, for example, LaAlO 3 or SrTiO 3
  • the rock salt structure material is employed as a buffer layer, template layer, and release layer.
  • the method comprises (a) growing a rock salt structure material layer on a perovskite oxide material substrate; (b) growing a protective layer comprising a lattice matched template material on the rock salt structure material layer; (c) depositing a colossal magneto-resistive layer on the protective layer; (d) fabricating a detector array; (e) bonding the detector array to a ROIC; (f) removing the rock salt structure material with water or other solution; and (g) the substrates falls off and is removed.
  • the growth and processing temperatures can be higher than those associated with a conventional technique in which the CMR material is grown directly on top of the ROIC, thus yielding a CMR material of higher quality and higher crystal orientation, and higher temperature coefficient of resistance.
  • Advantages associated with the embodiments of the present method include not only the ability to produce a detector of the requisite film quality, but one which satisfies the temperature coefficient of resistance and fabrication temperature constraints. In addition, once the fabrication is complete, the substrate can be easily removed.
  • FIGS. 1A–D are schematic representations of a detector constructed in accordance with a first preferred embodiment of the invention comprising a rock salt structure material as a substrate.
  • FIGS. 2A–E are schematic representations of a detector constructed in accordance with a second preferred embodiment of the invention comprising a perovskite oxide material as the substrate and a rock salt structure material as the buffer layer, template layer, and release layer.
  • FIG. 3 is a graphical representation of a pre-substrate removal x-ray diffraction pattern associated with an embodiment of the present invention in which SrTiO 3 was deposited on NaCl with Pd as a thin buffer layer.
  • FIG. 4 is a graphical representation of a post-substrate removal x-ray diffraction pattern associated with the embodiment depicted in FIG. 3 .
  • Rock salt structure materials have cubic crystal structures with lattice constants suitable for the growth of such CMR materials.
  • CMR materials have perovskite structures with an a and a b lattice constant of approximately 3.8 to 3.9 ⁇ .
  • Rock salt has a cubic crystal structure.
  • FIGS. 1A–D are schematic representations of a detector 110 ( FIG. 1D ) constructed in accordance with a first preferred embodiment of the invention comprising a rock salt structure material as a substrate.
  • the method of fabricating detector 110 comprises the following series of steps. First, a protective layer 120 comprising a lattice matched template material, such as, for example, a colossal magneto-resistive material, is grown so as to envelop a rock salt structure material substrate 130 ( FIG. 1A ).
  • Substrate 130 comprises either rock salt (i.e., NaCl) or a material having the structure of rock salt such as, for example, LiF, NaF, KF, or KCl.
  • rock salt i.e., NaCl
  • a material having the structure of rock salt such as, for example, LiF, NaF, KF, or KCl.
  • LiF is employed as the rock salt structure material.
  • a colossal magneto-resistive layer 140 is deposited on a deposition surface 121 of protective layer 120 ( FIG. 1B ).
  • a detector array is fabricated by adding contacts and processing devices 150 to an interconnect surface 141 of colossal magneto-resistive layer 140 , and a bonded structure is fabricated by bonding the detector array to a circuit 160 such as a readout integrated circuit ( FIG. 1C ).
  • rock salt structure material substrate 130 is removed from the bonded structure ( FIG. 1D ). Removal of rock salt structure material substrate 130 can be accomplished by dissolving the rock salt structure material substrate in water. Excess rock salt structure material/water solution can then be removed by a water rinse and a method such as evaporation, triple-point, or freeze drying.
  • protective layer 120 By growing protective layer 120 so as to envelop rock salt structure material substrate 130 , the rock salt structure material substrate is protected so that photolithography or mesa etching can be employed in an optional further step to remove protective layer 120 . If photolithography is employed, it is recommended that pure alcohol be used. If mesa etching is employed, it is recommended that dry etching be used.
  • FIGS. 2A–E are schematic representations of a detector 210 ( FIG. 2E ) constructed in accordance with a second preferred embodiment of the invention comprising a perovskite oxide material as the substrate and a rock salt structure material as the buffer layer, template layer, and release layer.
  • the method of fabricating detector 210 comprises the following series of steps.
  • a rock salt structure material layer 220 is grown on a perovskite oxide material substrate 230 ( FIG. 2A ).
  • Layer 220 comprises either rock salt (i.e., NaCl) or a material having the structure of rock salt such as, for example, LiF, NaF, KF, or KCl.
  • LiF is employed as the rock salt structure material.
  • Substrate 230 comprises a perovskite oxide material such as, for example, SrTiO 3 or LaAlO 3 .
  • a protective layer 240 comprising a lattice matched template material is grown on rock salt structure material layer 220 ( FIG. 2B ), followed by the deposition of a colossal magneto-resistive layer 250 on a deposition surface 241 of protective layer 240 ( FIG. 2C ).
  • a detector array is fabricated by adding contacts and processing devices 260 to an interconnect surface 251 of colossal magneto-resistive layer 250 , and a bonded structure is fabricated by bonding the detector array to a circuit 270 such as a readout integrated circuit ( FIG. 2D ).
  • rock salt structure material substrate 230 is removed from rock salt structure material layer 220
  • rock salt structure material substrate 220 is removed from protective layer 240 ( FIG. 2E ).
  • Removal of rock salt structure material layer 220 can be accomplished by dissolving the rock salt structure material layer in water. Excess rock salt structure material/water solution can then be removed by a water rinse and a method such as evaporation, triple-point, or freeze drying.
  • photolithography or mesa etching can be employed to remove protective layer 240 . If photolithography is employed, it is recommended that pure alcohol be used. If mesa etching is employed, it is recommended that dry etching be used.
  • FIG. 3 is a graphical representation of a pre-substrate removal x-ray diffraction pattern associated with an embodiment of the present invention in which an SrTiO 3 film was deposited on NaCl with Pd serving as a thin buffer layer.
  • the embodiment represented by the graph depicted in FIG. 3 shows strong crystal ( 110 ) orientation before the substrate removal.
  • FIG. 4 is a graphical representation of a post-substrate removal x-ray diffraction pattern associated with the embodiment depicted in FIG. 3 .
  • the x-ray diffraction pattern shows that the strong crystal orientation of the SrTiO 3 film remained even after the NaCl substrate had been removed.
  • the embodiments of the present invention therefore, provide a method of fabricating a CMR detector using a thin film transfer method with a rock salt structure material employed as either a substrate in a first preferred embodiment, or as a buffer layer, template layer, and release layer in a second preferred embodiment.
  • Advantages associated with the method include not only the ability to produce a detector of the requisite film quality, but one which satisfies the temperature coefficient of resistance and fabrication temperature constraints.

Abstract

A method of fabricating a colossal magneto-resistive detector using a thin film transfer method includes the use of a perovskite oxide material as a substrate, and a rock salt structure material as a buffer layer, template layer, and release layer. Advantages associated with the method include not only the ability to produce a detector of the requisite film quality, but one which satisfies the temperature coefficient of resistance and fabrication temperature constraints. In addition, when employed as either the substrate or the buffer layer, template layer, and release layer, after bonding the rock salt structure material can be easily removed using water, and the excess rock salt structure material/water solution can then be removed with known techniques.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. patent application Ser. No. 09/550,623, filed on Apr. 17, 2000 which will issue as U.S. Pat. No. 6,708,392 on 23 Mar. 2004 which is herein incorporated by reference in its entirety.
GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for government purposes without the payment of any royalties therefor.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to uncooled infrared detectors and focal plane arrays, and more specifically to a method of fabricating a detector using rock salt as a removable substrate. The invention relates even more specifically to a method of fabricating a colossal magneto-resistive detector using a rock salt structure material.
2. Description of Related Art
Uncooled infrared thermal detectors have recently been developed into large-size focal plane arrays (hereinafter “FPA”). Use of a microbolometer is one successful method for infrared detection at room temperature. A microbolometer-type FPA typically employs vanadium oxide on silicon nitride with a micro-mechanically machined air bridge structure. The temperature coefficient of resistance for vanadium oxide is approximately 2%. The air bridge structure is built directly on a silicon readout integrated circuit (“ROIC”). Growth of detector materials directly on the ROIC restricts the material thin film growth temperature to less than 550° C. as a result of the thermal budget limitation associated with the ROIC.
The use of colossal magneto-resistive (“CMR”) materials for uncooled infrared detectors is described in Goyal et al., A., AMaterial Characteristics of Perovskite Manganese Oxide Thin Films for Bolometric Applications, ′ Applied Physics Letters, Vol. 71 (17) (27 Oct. 1997), pp. 2535–2537. CMR materials demonstrate an exceptionally large change in resistance with temperature as they transition from a ferromagnetic to a non-ferromagnetic phase. The transition temperature can be adjusted through appropriate selection of materials and process conditions. The results have demonstrated the feasibility of growing CMR thin films on perovskite oxide material substrates such as LaAlO3 and SrTiO3 with a resultant temperature coefficient of resistance of greater than 7%. However, the temperature for growth of the CMR material, however, must be relatively high (i.e., greater than 700° C.), which makes it difficult to grow directly on the ROIC.
CMR materials have a perovskite crystal structure with a square base. The lattice constant “a” of the square base of a CMR material is approximately 3.8 to 3.9 Å depending on the material composition. As indicated above, CMR thin films have been successfully grown on perovskite oxide substrates such as LaAlO3 and SrTiO3, and exhibit a good crystal orientation and a high temperature coefficient of resistance. These perovskite oxide substrate materials are employed because of the correspondence of their crystal structure and lattice constant to those of CMR materials. For example, SrTiO3 has a cubic crystal structure with a lattice constant of 3.905 Å, and LaAlO3 has a pseudo-cubic crystal structure with a lattice constant of 3.79 Å. These properties facilitate the growth of a CMR material on LaAlO3 and SrTiO3 with a resultant high crystal orientation and quality. The detector material can be bonded to a ROIC, then the substrate is removed. A disadvantage associated with use of these materials, however, is that both LaAlO3 and SrTiO3 are very difficult to remove by etching once the detector array has been bonded to the ROIC.
Therefore, a general need exists to provide a method of fabricating an uncooled infrared detector which both satisfies the temperature coefficient of resistance and fabrication temperature constraints, and also provides a detector of the requisite film quality. An even more specific need exists to provide a CMR transferred thin film method in which the substrate can be easily removed.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of fabricating an uncooled infrared detector that produces a detector of the requisite film quality, satisfies the temperature coefficient of resistance, and easy to fabricate. Accordingly, in a first preferred embodiment, the present invention advantageously relates to a method of fabricating a CMR detector using a thin film transfer method with a rock salt structure material as a substrate. The method comprises (a) growing a protective layer comprising a lattice matched template material so as to envelop a rock salt structure material substrate; (b) depositing a colossal magneto-resistive layer on a deposition surface of the protective layer; (c) fabricating a detector array (d) bond the detector array to a ROIC; and (e) removing the rock salt structure material substrate from the bonded structure.
By using a rock salt structure material such as, for example, NaCl, LiF, NaF, KF, or KCl as the substrate, a high quality epitaxial CMR material with a high temperature coefficient of resistance can be fabricated. The substrate can be easily removed using water, and the excess rock salt structure material/water solution can then be removed by a method such as evaporation, triple-point, or freeze drying.
In a second preferred embodiment, the present invention relates to a method in which a perovskite oxide material such as, for example, LaAlO3 or SrTiO3 is employed as the substrate, and the rock salt structure material is employed as a buffer layer, template layer, and release layer. The method comprises (a) growing a rock salt structure material layer on a perovskite oxide material substrate; (b) growing a protective layer comprising a lattice matched template material on the rock salt structure material layer; (c) depositing a colossal magneto-resistive layer on the protective layer; (d) fabricating a detector array; (e) bonding the detector array to a ROIC; (f) removing the rock salt structure material with water or other solution; and (g) the substrates falls off and is removed.
By employing either of the aforementioned embodiments, the growth and processing temperatures can be higher than those associated with a conventional technique in which the CMR material is grown directly on top of the ROIC, thus yielding a CMR material of higher quality and higher crystal orientation, and higher temperature coefficient of resistance.
Advantages associated with the embodiments of the present method include not only the ability to produce a detector of the requisite film quality, but one which satisfies the temperature coefficient of resistance and fabrication temperature constraints. In addition, once the fabrication is complete, the substrate can be easily removed.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiments, the appended claims, and the accompanying drawings. As depicted in the attached drawings:
FIGS. 1A–D are schematic representations of a detector constructed in accordance with a first preferred embodiment of the invention comprising a rock salt structure material as a substrate.
FIGS. 2A–E are schematic representations of a detector constructed in accordance with a second preferred embodiment of the invention comprising a perovskite oxide material as the substrate and a rock salt structure material as the buffer layer, template layer, and release layer.
FIG. 3 is a graphical representation of a pre-substrate removal x-ray diffraction pattern associated with an embodiment of the present invention in which SrTiO3 was deposited on NaCl with Pd as a thin buffer layer.
FIG. 4 is a graphical representation of a post-substrate removal x-ray diffraction pattern associated with the embodiment depicted in FIG. 3.
 DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be disclosed in terms of the currently perceived preferred embodiments thereof.
To facilitate the growth of materials with the desired crystal orientation for use in infrared detectors, a basic epitaxial relation and lattice match must exist between the substrate material and the CMR material. Rock salt structure materials have cubic crystal structures with lattice constants suitable for the growth of such CMR materials.
CMR materials have perovskite structures with an a and a b lattice constant of approximately 3.8 to 3.9 Å. Rock salt has a cubic crystal structure. LiF has a lattice constant a=4.02 Å, which matches CMR material very well, with only slight tensile strain. NaCl has a lattice constant a=5.64 Å, hence, to match the lattice constant, CMR materials may be grown epitaxially, but with slight tensile strain along the <110> direction of the NaCl. KF has a lattice constant a=5.34758 Å, hence, to match the lattice constant, CMR materials may be grown epitaxially, but with slight compressive strain along the <10> direction of the KF.
Therefore, when a rock salt structure material is used as a substrate, CMR materials can be grown directly on such a substrate. FIGS. 1A–D are schematic representations of a detector 110 (FIG. 1D) constructed in accordance with a first preferred embodiment of the invention comprising a rock salt structure material as a substrate. The method of fabricating detector 110 comprises the following series of steps. First, a protective layer 120 comprising a lattice matched template material, such as, for example, a colossal magneto-resistive material, is grown so as to envelop a rock salt structure material substrate 130 (FIG. 1A). Substrate 130 comprises either rock salt (i.e., NaCl) or a material having the structure of rock salt such as, for example, LiF, NaF, KF, or KCl. In a preferred embodiment, LiF is employed as the rock salt structure material.
Next, a colossal magneto-resistive layer 140 is deposited on a deposition surface 121 of protective layer 120 (FIG. 1B). A detector array is fabricated by adding contacts and processing devices 150 to an interconnect surface 141 of colossal magneto-resistive layer 140, and a bonded structure is fabricated by bonding the detector array to a circuit 160 such as a readout integrated circuit (FIG. 1C).
Finally, rock salt structure material substrate 130 is removed from the bonded structure (FIG. 1D). Removal of rock salt structure material substrate 130 can be accomplished by dissolving the rock salt structure material substrate in water. Excess rock salt structure material/water solution can then be removed by a water rinse and a method such as evaporation, triple-point, or freeze drying.
By growing protective layer 120 so as to envelop rock salt structure material substrate 130, the rock salt structure material substrate is protected so that photolithography or mesa etching can be employed in an optional further step to remove protective layer 120. If photolithography is employed, it is recommended that pure alcohol be used. If mesa etching is employed, it is recommended that dry etching be used.
FIGS. 2A–E are schematic representations of a detector 210 (FIG. 2E) constructed in accordance with a second preferred embodiment of the invention comprising a perovskite oxide material as the substrate and a rock salt structure material as the buffer layer, template layer, and release layer. The method of fabricating detector 210 comprises the following series of steps. First, a rock salt structure material layer 220 is grown on a perovskite oxide material substrate 230 (FIG. 2A). Layer 220 comprises either rock salt (i.e., NaCl) or a material having the structure of rock salt such as, for example, LiF, NaF, KF, or KCl. In a preferred embodiment, LiF is employed as the rock salt structure material. Substrate 230 comprises a perovskite oxide material such as, for example, SrTiO3 or LaAlO3.
Next, a protective layer 240 comprising a lattice matched template material is grown on rock salt structure material layer 220 (FIG. 2B), followed by the deposition of a colossal magneto-resistive layer 250 on a deposition surface 241 of protective layer 240 (FIG. 2C). A detector array is fabricated by adding contacts and processing devices 260 to an interconnect surface 251 of colossal magneto-resistive layer 250, and a bonded structure is fabricated by bonding the detector array to a circuit 270 such as a readout integrated circuit (FIG. 2D).
Finally, perovskite oxide material substrate 230 is removed from rock salt structure material layer 220, and rock salt structure material substrate 220 is removed from protective layer 240 (FIG. 2E). Removal of rock salt structure material layer 220 can be accomplished by dissolving the rock salt structure material layer in water. Excess rock salt structure material/water solution can then be removed by a water rinse and a method such as evaporation, triple-point, or freeze drying.
In an optional further step, photolithography or mesa etching can be employed to remove protective layer 240. If photolithography is employed, it is recommended that pure alcohol be used. If mesa etching is employed, it is recommended that dry etching be used.
EXAMPLE
FIG. 3 is a graphical representation of a pre-substrate removal x-ray diffraction pattern associated with an embodiment of the present invention in which an SrTiO3 film was deposited on NaCl with Pd serving as a thin buffer layer. The embodiment represented by the graph depicted in FIG. 3 shows strong crystal (110) orientation before the substrate removal.
FIG. 4 is a graphical representation of a post-substrate removal x-ray diffraction pattern associated with the embodiment depicted in FIG. 3. The x-ray diffraction pattern shows that the strong crystal orientation of the SrTiO3 film remained even after the NaCl substrate had been removed.
The embodiments of the present invention, therefore, provide a method of fabricating a CMR detector using a thin film transfer method with a rock salt structure material employed as either a substrate in a first preferred embodiment, or as a buffer layer, template layer, and release layer in a second preferred embodiment. Advantages associated with the method include not only the ability to produce a detector of the requisite film quality, but one which satisfies the temperature coefficient of resistance and fabrication temperature constraints.
While only certain preferred embodiments of this invention have been shown and described by way of illustration, many modifications will occur to those skilled in the art. For example, while the method has been described in the context of a colossal magneto-resistive detector application, it is equally applicable to any service requiring a high quality film produced by a thin film transfer method which uses an easily removable material as either a substrate or as a layer. By way of further example of modifications within the scope of this invention, while the method has been described in the first and second preferred embodiments respectively as comprising the use of a single rock salt structure material substrate or layer, another embodiment could comprise the use of a plurality of the aforementioned substrates or layers.
It is, therefore, desired that it be understood that it is intended herein to cover all such modifications that fall within the true spirit and scope of this invention.

Claims (9)

1. A method of fabricating a colossal magneto-resistive detector using a thin film transfer method, said method of fabricating comprising:
(a) growing a rock salt structure material layer on a perovskite oxide material substrate;
(b) growing a protective layer comprising a lattice matched template material on said rock salt structure material layer;
(c) depositing a colossal magneto-resistive layer on said protective layer;
(d) fabricating a detector array by adding contacts and processing devices to an interconnect surface of said colossal magneto-resistive layer;
(e) fabricating a bonded structure by bonding said detector array to a circuit;
(f) removing said perovskite oxide material substrate from the rock salt structure material layer; and
(g) removing said rock salt structure material layer from the protective layer.
2. A method according to claim 1, wherein said perovskite oxide material substrate is a material selected from the group consisting of LaAlO3 and SrTiO3.
3. A method according to claim 1, wherein said rock salt structure material substrate is a material selected from the group consisting of NaCl, LiF, NaF, KF, and KCl.
4. A method according to claim 1, wherein said lattice matched template material is a colossal magneto-resistive material.
5. A method according to claim 1, wherein said circuit is a readout integrated circuit.
6. A method according to claim 1, wherein step (f) comprises an etching method.
7. A method according to claim 1, wherein step (g) comprises dissolving said rock salt structure material substrate in water, and said method further comprises:
(h) removing excess rock salt structure material/water solution.
8. A method according to claim 7, wherein step (h) is carried out by a water rinse and a method selected from the group consisting of evaporation, triple-point, and freeze drying.
9. A method according to claim 1, further comprising: removing said protective layer by etching.
US10/805,669 2000-04-17 2004-03-22 Method of fabricating a colossal magneto-resistive detector using a thin film transfer method Expired - Fee Related US6910261B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/805,669 US6910261B1 (en) 2000-04-17 2004-03-22 Method of fabricating a colossal magneto-resistive detector using a thin film transfer method

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/550,623 US6708392B1 (en) 2000-04-17 2000-04-17 Method of fabricating uncooled IR detector and arrays using colossal magneto-resistive materials and rock salt structure material substrates
US10/805,669 US6910261B1 (en) 2000-04-17 2004-03-22 Method of fabricating a colossal magneto-resistive detector using a thin film transfer method

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09/550,623 Division US6708392B1 (en) 2000-04-17 2000-04-17 Method of fabricating uncooled IR detector and arrays using colossal magneto-resistive materials and rock salt structure material substrates

Publications (1)

Publication Number Publication Date
US6910261B1 true US6910261B1 (en) 2005-06-28

Family

ID=31978919

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/550,623 Expired - Fee Related US6708392B1 (en) 2000-04-17 2000-04-17 Method of fabricating uncooled IR detector and arrays using colossal magneto-resistive materials and rock salt structure material substrates
US10/805,669 Expired - Fee Related US6910261B1 (en) 2000-04-17 2004-03-22 Method of fabricating a colossal magneto-resistive detector using a thin film transfer method

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/550,623 Expired - Fee Related US6708392B1 (en) 2000-04-17 2000-04-17 Method of fabricating uncooled IR detector and arrays using colossal magneto-resistive materials and rock salt structure material substrates

Country Status (1)

Country Link
US (2) US6708392B1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210148004A1 (en) * 2017-06-13 2021-05-20 Board Of Trustees Of Michigan State University Method for fabricating epitaxial halide perovskite films and devices

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5465475A (en) 1992-07-30 1995-11-14 Ricoh Co., Ltd. Method of forming a thin film magnetic head
US5507080A (en) 1993-12-07 1996-04-16 Matsushita Electric Industrial Co., Ltd. Method of manufacturing a capacitance sensor
US5658355A (en) 1994-05-30 1997-08-19 Alcatel Alsthom Compagnie Generale D'electricite Method of manufacturing a supercapacitor electrode
US20010037565A1 (en) 1998-12-03 2001-11-08 Chandrika Prasad Process for forming a multi-level thin-film electronic packaging structure
US6510597B2 (en) 1999-08-31 2003-01-28 Pioneer Corporation Surface acoustic wave device and method of manufacturing the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5465475A (en) 1992-07-30 1995-11-14 Ricoh Co., Ltd. Method of forming a thin film magnetic head
US5507080A (en) 1993-12-07 1996-04-16 Matsushita Electric Industrial Co., Ltd. Method of manufacturing a capacitance sensor
US5658355A (en) 1994-05-30 1997-08-19 Alcatel Alsthom Compagnie Generale D'electricite Method of manufacturing a supercapacitor electrode
US20010037565A1 (en) 1998-12-03 2001-11-08 Chandrika Prasad Process for forming a multi-level thin-film electronic packaging structure
US6510597B2 (en) 1999-08-31 2003-01-28 Pioneer Corporation Surface acoustic wave device and method of manufacturing the same

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
A. Goyal, et al. Material Characteristics of Perovskite Manganese Oxide Thin Films for Biometric Applications, Applied Physics Letters 71, Oct. 27, 1997, pp. 2535-2537.
Z. Trajanovic, et al. "Growth of Colossal Magnetoresistance Thin Films on Silicon," Applied Physics Letters 69, Aug. 12, 1998, pp. 1005-1007.

Also Published As

Publication number Publication date
US6708392B1 (en) 2004-03-23

Similar Documents

Publication Publication Date Title
Muralt Micromachined infrared detectors based on pyroelectric thin films
Gunapala et al. 640/spl times/486 long-wavelength two-color GaAs/AlGaAs quantum well infrared photodetector (QWIP) focal plane array camera
US5380669A (en) Method of fabricating a two-color detector using LPE crystal growth
US6495828B1 (en) Ferroelectric/pyroelectric infrared detector with a colossal magneto-resistive electrode material and rock salt structure as a removable substrate
US6910261B1 (en) Method of fabricating a colossal magneto-resistive detector using a thin film transfer method
US3671102A (en) Lamellar eutectic insb sb films as infrared polarizers
US6699521B1 (en) Method of fabricating a ferroelectric/pyroelectric infrared detector using a crystallographically oriented electrode and a rock salt structure material substrate
JP3828443B2 (en) Infrared imaging device and manufacturing method thereof
US6774014B1 (en) Method of fabricating spherical quantum dots device by combination of gas condensation and epitaxial technique
MAGNETO-RESISTIVE Tidrow et al.
US10488263B2 (en) Thin film structure for micro-bolometer and method for fabricating the same
US10371571B2 (en) Thin film structure for micro-bolometer and method for fabricating the same
US4743949A (en) Infrared optical-electronic device
Jhabvala et al. Advanced substrate thinning process for GaAs-based devices
Johnson et al. Status of HgCdTe/Si technology for large format infrared focal plane arrays
JPH01117376A (en) Edge junction type single crystal thin film superconductor tunnel junction element and manufacture thereof
Zogg et al. Two-dimensional monolithic lead chalcogenide infrared sensor array on silicon read-out chip
Masek et al. Photovoltaic infrared sensor array in heteroepitaxial narrow gap lead-chalcogenides on silicon
WO2005062394A1 (en) Bolometer
JP2592834B2 (en) Crystal article and method for forming the same
Zogg et al. Epitaxial lead chalcogenides on fluoride covered silicon substrates: Properties and infrared device fabrication
JP2564526B2 (en) Pyroelectric infrared array element and manufacturing method thereof
JP2010062268A (en) BiTe-BASED THIN FILM, METHOD OF MANUFACTURING THE SAME, AND INFRARED SENSOR
JPH08167740A (en) Pyroelectric infrared thin film element
Asaoka et al. Stress evolution during epitaxial growth of SrO films on hydrogen-terminated Si (111) surfaces

Legal Events

Date Code Title Description
AS Assignment

Owner name: SECRETARY OF THE ARMY, UNITED STATES OF AMERICA AS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TIDROW, MELMEI;TIDROW, STEVEN;REEL/FRAME:015417/0297;SIGNING DATES FROM 20000411 TO 20000412

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 20130628